Danny Kirwan, who joined Fleetwood Mac as a guitarist at age 18 in 1968, died on Friday, June 8. His death was reported by the band’s co-founder, Mick Fleetwood, on his Facebook page. Kirwan played, sang and wrote songs for four of the band’s albums between 1969-1972, including Bare Trees, for which he was the principal songwriter. The location and cause of death was not known as of early Saturday morning.